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Process Heat

Huge potential but little implementation so far – this is how one could describe the global situation of Solar Heat for Industrial Processes (SHIP). Although experts acknowledge that process heat shows the greatest potential of all solar heating and cooling applications, the share of SHIP systems in total installed solar thermal capacity has remained below 1 %. To tackle some of the barriers, such as missing standardisation, system costs and reliability, the INSHIP project funded by EU Horizon 2020 was launched in early 2017. It aims to devise a European Common Research and Innovation Agenda (ECRIA) on SHIP within the next four years. The project is coordinated by the German Fraunhofer Institute for Solar Energy Systems ISE and involves 28 European research institutions from twelve countries.

Industrial solar heat is far from being a standard yet, but it is more widespread than you might think. The first World Map of Solar Process Heat Specialists shows 71 companies in 22 countries which reported almost 400 reference systems. Together with additional plants included in the online portal ship-plants.info, the world market for industrial process heat comprises at a minimum 525 plants with an collector or mirror area of at least 416,414 m².

Amul Fed Dairy based in Gandhinagar in the western Indian state of Gujarat is one of the country’s biggest milk-processing plants and is owned by Gujarat Cooperative Milk Marketing Federation. In October 2016, it had a 560 m² parabolic trough collector field installed to allow for the feed-in of solar steam into the factory grid. The INR 15.7 million (around EUR 220,000) system was set up by Thermax, an Indian manufacturer of solar heating and cooling technology. It was designed to reduce gas consumption by about 50,000 m³ each year – which barely meets 0.59 % of the energy demand for the entire facility. India is one of the world’s largest producers of milk, with an annual output of 140 million tonnes, a figure that will probably rise to 200 million by 2022.

At the request of the Pakistani government, the United Nations Industrial Development Organization (UNIDO) has launched a project titled Sustainable Energy Initiative for Industries in Pakistan to promote the adoption of renewable energy and energy efficiency technologies and services in Pakistan’s industries. But despite the country’s great energy demand and huge solar potential, the study says little about solar thermal usage

Austrian collector manufacturer Tisun is currently the supplier for three major projects in Kuwait, Abu Dhabi and Qatar. Its subsidiary, Tisun GCC with two Dubai stakeholders, have been the ones helping the company enter the Arab markets. Since 2010, Tisun has had a local subsidiary in Dubai, Tisun GCC. Tisun’s first reference project in the region was a 500 m² solar field built in 2012 for a food-processing factory and it has opened many doors since.

The Solar Thermal Federation of India (STFI) and the Indo-German Chamber of Commerce (IGCC) have teamed up for the international Solar Payback project, which aims to increase the use of solar thermal energy in industrial processes. The photo shows the partners during the Kick-Off Meeting in Mumbai, India, on 16 December 2016. Supported by the German Federal Environment Ministry funded by the International Climate Initiative, the three-year project will be implemented in India, South Africa, Mexico and Brazil. It is coordinated by the German Solar Association BSW-Solar and eleven partner organisations: three German companies, plus each target country’s national solar industry association and German chamber of commerce.

India has been witnessing renewed interest in solar thermal in the wake of some successful installations. Dish-type concentrating systems have the potential to generate hot water above 100 °C. But in many places, insufficient space or unsuitable roof structures are roadblocks to increased deployment. Several Indian start-ups have used evacuated tube collectors (ETC) with compound parabolic concentrators (CPC), popularly known as non-imaging collectors in India, for solar process heat applications which require medium-pressure steam at around 150 °C. These collectors consist of evacuated double-glass tubes with bent aluminium mirrors underneath. The CPC mirror guarantees that fewer tubes are required per unit area and over 90 % of the gross collector area is used optically. So far, the aluminium sheets for the systems have been imported, but one local manufacturer will start operations soon.

The 191 solar process heat projects which have made it into the online database add up to an installed capacity of 0.11 GWth (0.159 million m²), which is only a small fraction of the potential estimated for this type of application. To quantify the technology’s global opportunities, the researchers from the now-completed four-year Task 49 / IV, Solar Heat Integration in Industrial Processes, analysed the results of several national studies which had tried to determine the potential of solar process heat while considering restrictions such as temperature range and the space available for the systems (see the chart on the left). “For Europe, where mainly non-concentrating collectors had been investigated, the percentage of technical potential for solar process heat related to the total industrial heat demand is around 3 to 4 %,” was the conclusion by the authors of the attached report Potential studies on solar process heat worldwide.

The IEA’s Medium-Term Renewable Energy Market Report or MTRMR 2016 again includes a chapter on renewable heating and cooling – and it’s growing in size. The 282-page document published from Singapore on 25 October analyses on 47 pages the current and future market development of four renewable heating technologies: biomass, solar thermal, geothermal and heat pumps. The IEA began to add a renewable heating chapter to its MTRMR in 2013 – back then, it had only 14 pages. The authors of this year’s edition emphasise the fact that onshore wind and solar PV are the only renewable technologies on track for a 2 °C target.

The new interest subvention scheme for Concentrating Solar Thermal (CST) technologies administrated by the Indian Renewable Energy Development Agency (IREDA) is now open for applications. The scheme has been developed in cooperation with the UN Industrial Development Organisation (UNIDO) during the GEF-UNIDO-MNRE project, which focuses on increasing the deployment of concentrating solar thermal systems for process heat applications in India. “Technology providers or beneficiaries can use a short-term bridge loan at normal interest rates for pre-financing the 30 % capital subsidy that the Ministry of New and Renewable Energy grants for CST technologies,” explained Dr Anil Misra, National Project Manager at UNIDO (see photo). IREDA also hands out long-term loans covering up to 45 % of the benchmark system cost at 5 % lower-than-usual interest rates. The remaining 25 % are required as equity by the beneficiary.